Embossing shells and method for producing and assembling same



July 10, 1962 R. F NELSON 3,042,995

EMBOSSING SHELLS AND METHOD FOR PRODUCING AND ASSEMBLING SAME Filed Dec. 5, 1959 5 Sheets-Sheet 1 ATTORNEYS July 10, 1962 R. F. NELSON EMBOSSING SHELLS AND METHOD FOR PRODUCING AND ASSEMBLING SAME Filed Dec. 3, 1959 5 Sheets-Sheet 3 152 EH 6d 2 nun 1165 523 1.9a

f INVENTOR:

l i F N l ATTORNEYS.

July 10, 1962 R; F. NELSON 3,042,996

EMBOSSING SHELLS AND METHOD FOR PRODUCING AND ASSEMBLING SAME Filed Dec. 3, 1959 5 Sheets-Sheet 4 F i yull.

INVENTOR.

Rokezj' E N,e,lspn

AITORNEISS'.

July 10, 1962 R. F. NELSON EMBOSSING SHELLS AND METHOD FOR 3,042,996 PRODUCING AND ASSEMBLING SAME 5 Sheets-Sheet 5 Filed Dec. 5, 1959 WM N own

m I 3 W3 0 m 0mm m n M 9mm 3% E m mum m m f A mwm M I w mwm w I] P @R m w w m J wmm mm 9%. R w M6, Y 2-: B 3m 5% III! fl msm b6 NR m. mm 93 wow mu 7 3,0429% EMEGESHIG Sit-EELS AND METHOD FOR PR6- DUCING AND ASSEMELING SAME Robert E. Nelson, Hillside, Ni, assignor to Modern Engraving and Machine Company, Hillside, NJ, a corporation of New Jersey Filed Dec. 3, 1959, Ser. No. 855,999 16 Claims. (61. 29-14843) This invention relates to embossing, and in particular to the embossing of sheet materials, such as metal, paper, etc.

Embossing rolls capable of transferring designs or patterns to sheet materials are disclosed, for example, in Patent No. 2,662,002. It is the usual practice in this field for such embossing rolls to be constructed of solid metal. Due to this and other factors, the cost of such solid rolls is relatively high. As is understood, each set of matched rolls includes only one design or pattern. Thus, if it is desired by the manufacturer to produce embossed sheet metal products of a variety of designs, it will be necessary to purchase a separate set of embossing rolls for each design desired, as is understood.

It has been found that for these reasons, the promotion of new designs and patterns by manufacturers of the embossing rolls to manufacturers of the embossed sheet materials has been quite difiicult, inasmuch as only Very large producers have a suflicient volume to absorb the expensive costs involved in purchasing several sets of en1- bossing rolls with different designs thereon.

Some suggestion has been made as to the use of hollow or tubular embossing shells, rather than solid metallic embossing rolls. However, for one reason or another, it has not heretofore been the commercial practice to utilize matched, hollow embossing rolls, in place of the matched, solid metal embossing rolls.

Accordingly, it is a principalobject of the present invention to provide novel structures and procedures for mounting a pair of matched hollow or tubular embossing shells in coextensive and mating relationship, in operative position in an embossing machine, and particularly adapted to facilitate the precise mating of the one pattern on one of the shells with the complementary pattern on the other roll. A further and related object is to provide novel structures and procedures facilitating the assembly of a pair of matched hollow embossing shells in operative mating relationship in an embossing machine, and providing for the convenient changing of pairs of embossing shells, having different designs or patterns thereon, in operative position in the machine.

Broadly speaking, the invention contemplates a method of detachably assembling in an operative position a pair of matched and hollow embossing shells having mating patterns thereon, wherein said method comprises mounting said shells in rotatable positions in coextensive and substantially close relation with their, axes parallel; and rotating one of said shells relative to the other shell while maintaining said shells in bodily stationary position for bringing the patterns on said shells into precise registration with each other.

According to the invention, structure is also provided for mounting in operative embossing position a pair of matched and hollow embossing shells having mating patterns thereon, said structure comprising: shaft means drivingly and coaxially connected to each of said shells and extending axially outwardly therefrom at opposite ends thereof, means engaging said shaft means for rotatably mounting said shells coextensively and in substantially close relation with their axes in parallel, and alignable means operatively associated with said shells and constructed and arranged to be brought into radial alignment by relative rotation between said shells whereby to assure precise alignment of the patterns on said shells. In one scheme according to the invention, identical or substantially identical slots are provided in predetermined locations in corresponding radial end faces of said shells so that when said slots are brought into precise radial alignment, the patterns on said shells will be precisely mated. In another arrangement, driving gears are afiixed' to the hollow shells before the shells are mounted in operative positions, and the gears are provided with alignable marks or indicia. adapted, when aligned, to eflect precise registration of the patterns on the shells.

Further objects and advantages of the invention Will be in part obvious and in part pointed out hereinafter.

The novel features of the invention may be best made clear from the following description and accompanying drawings in which:

FIGURE 1 is an elevational viewof an exemplary apparatus for mounting a pair of hollow embossing shells, having matingpatterns thereon, in an operative position for embossing sheet materials fed therethrough;

FIGURE 2 is an enlarged, fragmentary and partially cut away perspective View of end faces of a pair of hollow embossing shells arranged in mating position, and indicating an exemplary procedure and structure for bringing the patterns on the embossing shells into precise alignment;

FIGURE 2a is a perspective View of a gauge plug shown in FIGURE 2 FIGURE 3 is a fragmentary, sectional view taken generally along line 3-3 of FIGURE 2;

FIGURE 4 is an enlarged, elevational view, partly in vertical section and partly cut away, of an exemplary embodiment for detachably mounting the embossing shells on a shaft;

FIGURES 5 and 6 are enlarged, fragmentary, vertical, sectional views showing modifications of certain structure shown in FIGURE 4;

FIGURE 7 is an enlarged and fragmentary elevational view partly in vertical section, and illustrating a modification of the structure shown in FIGURE 4 for engaging one end'of the hollow embossing shell;

FIGURE 8 is a fragmentary and enlarged elevational View, partly in vertical section, and partly cut away, showing another arrangement for mounting the hollow embossing shells on a shaft means;

FIGURES 9 and 10 are enlarged, fragmentary, vertical, sectional views showing modifications of certain structure shown in FIGURE 8;

FIGURE 11 is an enlarged and fragmentary vertical, sectional view taken generally along line 11-11 of FIG- URE 12 and of a further modified construction for connecting one end of a hollow embossing shell to a shaft means;

FIGURE 12 is a sectional view taken generally along line 12-12 of FIGURE 11; and

FIGURE 13 is an enlarged, vertical, sectional view of structure for mounting hollow embossing shells in operative and mating relationship, and constituting another embodiment of the invention.

Referring now to the drawings, there is illustrated in FIGURE 1 a machine 20 of the type disclosed in Patent No. 2,662,092 for mounting embossing members having cylindrical external surfaces in an operative embossing position. According to the present invention, the embossing members 22, 24 are hollow cylindrical shells having mating patterns thereon, and the present invention contemplates novel structures and procedures for manufacturing these shells and arranging them in operative position wherein the patterns thereon will be in precise registration or mating relationship with each other to achieve a high degree of accuracy, sharpness and Patented July It), 1962 l the slots 52, 54 are in precise alignment.

3 definition in the embossed sheet material produced thereby.

The machine. 20 is shown as comprising a pair of upright members or stanchions 26 mounted instationary position, with upper 28 and lower 30'bearing members arranged. therein for rotatably supporting shaft means 32, 34 and 36, 38'respectively, these shaft means being drivingly engaged to the shells 22, 24, as will be explained in more detail hereinbelow. Helical gears 40,

'- 7 42 are drivingly' engaged to the shaft means 34, 38,

and a prime mover 44 is shown as "being connected to the shaft means 32, as through a conventional speed re' ducer 46 and coupling 48, as discussed in Patent No.

In forming these embossed and matched shells, ac-,

cording to one embodiment of the invention, the blank or unembossed shells are first provided with aligned slots 50, 52, 54, 56 of uniform size in their radial end faces 58, 60, as indicated in FIGURE 2. As shown, they are arranged on each shell at diametrically opposite points,

' and they may be formed on one'or both ends of the shells, as by a milling operation. After these slots have been formed, the slots 50, 56 are respectively provided with threaded, axially extending holes 59, 61 therein, respectively, as indicated'in FIGURES 2 and 3.

. The shells 22, 2-4 will then be provided with mating or complementary projections and indentations thereon constituting the desired pattern, after which the slots 58,

52, 54, 56 may be ground to precision, in order to indicate precise registry of the patterns on the shells when these slots are in precise alignment.

The mating patterns may be formed 22, 24 by any suitable procedure. shell 22 may be connected to shaft means 32, 34 by I on the shells any or the structures hereinafter described, and arranged to have the desired pattern engraved thereon as in the manner disclosed in Patent No. 2,662,002, or it may have the desired pattern etched thereon, as in the manner disclosed in my copending application, Serial No. 668,377,

the disclosure of which is hereby incorporated herein by reference The second shell 24 may similarly'be connected to shaft means 36, 38 for rotation therewith, and both shells may be arranged in the machine 20 for imparting a' pattern on the shell 24 complementary to the pattern onthe shell 22, as-in the manner discussed in the aforesaid patent or copendin-g application. A gauge plug 62, as shownin FIGURE 2a, may be utilized for precisely aligning the slots 52, 54 before the pattern on shell 22 is rolled into the acid resist coating on the shell 24, in connection withthe etching procedure.

Thus, after the patterns have been so formed on shells 22, 24, it will be apparent that they will be in proper. and precise registration or mating relationship whenever plug 62, as shown, includes a finger engageable portion 64 and a base 66 of rectangular sectional configuration having a .width corresponding'to the width of the slots 52, 54, and of a sufiicient length to extend from one slot to-the other, for example, as indicated in FIGURE 2.'

In connection. with providing the matched patterns on the shells 22, 24, the procedure disclosed in the afore said patent may be utilized to provide for precise registration of the helical gears 40, 42.- As disclosed in that patent, these gears are provided with suitable means, for

I example, the marks or indicia 68, 70 shown in FIGURE The gauge For example, the V 2, adapted to be brought into radial alignment to assure proper registration and engagement of the gears.

FIGURE 2 illustrates an exemplary procedure according to the invention for arranging the mating or matched shells 22, 24 and gears 40, 42 in precise alignment or registration in their operative positions. Shaft sections 34, 38 extend from the shells and each end of the shells is provided with an outwardly flaring annular seat, as indicated by numeral 72 in FIGURE 3. A generally disclike member 74 having a hub portion 76 is fitted over the shaft sections 32, 34, 36, 38 at opposite ends of the shells 22, 24 and is formed with a frusto-conical surface 78 complementary to and adapted to seat against the flaring seats 72,such as in the manner shown in FIGURE 3. The hubs 76 may be drivingly connected to their respective shaft sections in any suitable manner, for example, the hubs and shaft sections may be formed with conventional keyways (not shown) adapted to be aligned and receive a conventional key (not shown), as will be understood.

Member 74 for the right hand end of the upper shell 22, shown in FIGURE 2, includes a radially projecting lug 80 disposed in the upper slot 50, andsecured to the shell 22 as by the bolt 82 extending through a slot 86 in the lug 80 and screwed into the hole 59. Slot 86 is of a size greater than the diameter of the shankof bolt 82, and lug 80 of a width smaller than the width of the slot 50, as indicated in FIGURES 2 and 3, for a purpose to become apparent as the description proceeds. The other members 74 on the shell 24and on the left handside of shell 22 may alsoinclude lugs similar to the lug 80, similarly arranged in theouter slots in the adjacent end faces of the shells, and secured thereto in the manner shown in FIGURE 3.

Collars 88, 90 are shown extending between the hubs 76 of the members 74 and the adjacent hearings in the machine 20 to prevent any axial movement of the shells when mounted in the machine. 'These collars may be drivingly engaged to their respective shafts, if desired, as by set screws 92, so as to prevent relative axial movement therebetween.

' Thus, when assembling shells 22, 24 in operative position, for example, in the machine 20, the shells will be arranged on their respective shaft sections 32, 34, 36, 38

.- by means of the members 74 and collars 88, 90 with the shaft sections being journalled in the bearings 28, 30. At this time, the gears 40, 42 are not attached to the shaft sections nor is the shaft section 32 connected to the prime mover 44. The shells 22, 24 are then rotated relative to each other until the slots 52, 54 of identical size are brought into precise alignment with each other. The gauge plug 62 will be used, as indicated in FIGURE 2, in connection with carrying out this aligning step. At this time, the gears '40, 42 willbe drivingly engaged to the right hand ends of the shaft sections 34, 38 and in meshing relation. The structure indicated in FIGURE 2 for drivingly connecting the gears to. their respective shaft sections includes axial grooves 94, 96 formed respectively in the gears and shaft sections, and complementary in shape so as to define a bore when aligned, into which a drive dowel 98 is inserted.

In the event there is need for slight adjustment between the gears 40, 42 in order to bring the marks 68, 70 into precise alignment, the bolt 82 connecting the lug 80 of member 74' to the right hand'end of top shell 22 will be loosened,and suitable means, such as a punch 100 and hammer 102 may be employed in the manner indicated for moving the gear 40 and shaft section 34 relative to the shell 22 the necessary amount. The gauge plug 62 may be left the position shown in FIGURE 2 during this adjusting movement in order to prevent any'disturbance in the registration of the patterns on the shells 22, 24-. After the gears have been meshed together with the marks 68, 70 thereon in perfect alignment, the bolt 82 will then be retightened into the hole 59 on the shell 22, and the coupling 43 may then be connected.

A disc-like plate 104, as shown in FIGURE 1, and of a diameter greater than the diameter of the shaft sections 34, 38 may be concentrically secured to the ends of these shaft sections adjacent the gears 49, 42, as by screws (not shown) extending through these plates and engaged in threaded holes 1% provided at the ends of these shaft sections, as shown in FIGURE 2.

A collar 168 may be arranged around the shaft sections 34, 38 between the bearings 28, 3t; and gears 49, 42, as indicated inFIGURE l, to hold these gears in proper axial position.

The shaft sections 32, 34 and 36, 38 have been'described as being separate and individual sections. However, ifdesired, sections 32, 34 may be part of a single shaft extending through the shell, and likewise with sections 36, 38.

Another arrangement for mounting the embossing shells on shafts is shown in FIGURE 4. In this embodiment, the shell 22a is again shown as including outwardly. flaring conical seats 72:: at each end thereof, and mandrels or end members 74a are arranged over the shaft 114 and include frusto-conical portions 78a complementary to and engaged against these annular seats 72a. These members 740. are also shown as including inwardly directed annular flanges 112 seating in counterbored portions 114 formed within opposite ends of the shell 22a. The hubs 76a on these members 74a are adapted to engage against the adjacent bearings 28, 31 in the machine 2% of FIGURE 1, and the reduced cylindrical portions 116 will be received in these hearings. Gear 49a is shown as being engaged over shaft 116, and drivingly connected thereto in any appropriate manner, such as that indicated in FIGURE 2, or by a key and keyway arrangement.

In this embodiment, the shaft 11% is of a suf'lcient length to extend outwardly of the left hand member 74a at one end, and outwardly of the gear 413a at the other end, and is shown as being provided with threads at each end. Nuts 118, 121 are screwed over these ends, and tightened against washers 122, 124 until the frusto-conical portions 78a of the members 74a are seated in firm frictional engagement with the flaring seats 72a on the shell 2211. As shown, a driving pin 126 may be fixedly secured to the left hand member 74a and extend radially therefrom into a slot 128 formed on the adjacent end of the shell to affect a positive driving connection therebetween.

When assembling shells in operative position, for example, in the machine of FIGURE 1 and by the structure shown in FIGURE 4, the end members 74a and upper and lower shells may be engaged to their respective shafts and with the portions 116 of the end members 74a engaged in the upper and lower bearings 23, 30. Before assembling the gears onto the shafts and tightening the nuts 118, 125), the patterns on shells will be brought into precise registration with each other, for example, by the same procedure as that discussed above in connection with.

the embodiment of FIGURE 2. The gears a, 42:: may then he arranged in driving engagement on their respective shafts, as by the structure shown in FIGURE 3. Inasmuch as the nuts 118, 120 have not yet been tightened, these gears and their respective shafts may be rotated without rotating the shells, whereby the gears may be conveniently brought into proper meshing relation, as by use of the marks 68, shown in FIGURE 2.

After the gears have been so arranged on the shafts, the nuts 118, will be tightened sufliciently so that rotation of the upper left hand end member 74a will be transmitted to the upper gear 40a to thereby rotate the lower gear and lower shell.

The left hand end member 74a may then be drivingly connected to the coupling 48, and a keyway 131! may be provided on portion 132 for this purpose.

FIGURES 5 and 6 show modifications of the means shown in FIGURE 4 for positively drivingly connecting shown asbeing mounted in a hole 138 in the member 74c and screwed into a threaded hole 140 in a shell 220;

FIGURE 7 illustrates a modification of the end members or mandrels shown in FIGURE 4. In this figure, the end member 74g is shown as including an external annular flange 178 engaging against the end face 58g of the shell 22g, and an annular recess 180 is formed in this member between the frusto-conical portioni78g and the end 182. The internal surface of the ends of the shell 22g is formed so as to provide the flaring seat 72g, and stepped or counterbored portions 184, 186, respectively. Portion 134 is disposed opposite the recess 180.

in the member 74g so as to form an annular space therewith, while the portion 186 is in engagement with the cylindrical surface 188 on the member 74g. A driving key 190 is shown attached to the flange 178, as by the screw 192, and is adapted to be fitted in the slot 52g to effect a positive driving connection between the member 74g and the shell. It will be understood that the left hand end of the shell 22g and the member 74g at that end may be constructed and arranged together in a manner similar to that shown in FIGURE 7.

FIGURE 8 illustrates another arrangement for mounting the shells on shaft means. In this figure, the shaft 142 is shown as being of an enlarged diameter having a frustoconical portion 78d integral therewith for engagement with the flaring seat 720? at the left end of the shell 22a. A separate collar 144 is mounted on the shaft 142 and having a frusto-conical portion 146 arranged in the flaring seat 72d at the right hand end of the shell 22d. The shaft 142 is provided with a threaded portion 148, and a nut 150 is screwed on this portion for tightening the collar 144 and portion 78d against their respective seats 72d. The nut may be provided with circumferentially spaced holes 152 adapted to be engaged by a suitable tool. A drive key 154 is shown as being secured to the portion 78d, as by screw 156, and extends radially outwardly from this portion into a slot 158 formed on the shell 22a.

The free ends of shaft 142 will be constructed so as to be engaged to the gearing at one end and the coupling 48 at the other. I

A pair of matching embossed shells engaged to shaft means, as shown in FIGURE 8, may be arranged in 0perative position in machine 20 by the procedures discussed above, as should be evident.

FIGURES 9- and 10 show modifications of the structure shown in FIGURE 8 for positively drivingly connecting the shaft 142 to the shell 22d. In FIGURE 9, the frusto-conical portion 78e is shown as being provided on an annular collar 160 extending around the shaft 142@ and drivingly connected thereto, as by the key 162 mounted in aligned keyways 164, 166 in the shaft 142e and collar 160, respectively. A driving key in the form of a pin 154a is secured in radial hole 168 in the collar 161 and extends into the slot 1582 on the shell 22c.

In FIGURE 10, the end of the shell is shown as being counterbored, and an annular flange 170 formed on the shaft 142i is engaged or seated within this counterbore 172 on the shell 22 as shown. A bolt 174 is mounted in the flange 170 and is screwed into a threaded hole 176 in the shell, as indicated.

FIGURES 11 and 12 show a further modificationof structure for mounting the shells on shaft means. The structure of this embodiment is particularly applicable for use with shells having a relatively large diameter compared to their axial length. As shown, the righthand end member 74h is in the form of a centrally apertured disc having a flange 194- thereon seated in a counterbored portion 196 'at the end of the shell 22h, and with bolts 198 extending through this flange 194 and being screwed in threaded holes 200 in the shell to secure the disc in registration.

accesseposition. The member'74h is provided'with a centrally arranged recess 202 in 'which is mounted a circular ad justing plate 204 having a hub 206 thereon. The plate 204 is shown as being angularly adjustably secured to the member 74h as by bolts 208 extending through enlarged arcuate slots 210 in the plate 294 and screwed into threaded holes 212 in the disc member 74H.

Aligned keyways 214, 216 are provided'onthe hub 206 of plate'204, andon shaft-means 34h, and a key' 218 is engaged in these keyways to effect a driving connection therebetween, as shown.

A pair of'lugs 220, 222 are shown as depending radially from the hub 2%, and a pin 224 is mounted in the disc member 7411 having a narrow fiat head 226 disposed between these lugs 220, 222. Adjusting screws 228, 230" 23i) in the desired directions to efiect rotation of the plate 2G4 and shaft 3411 as a unit and relative to the member 74h. When the adjustment has been completed, the bolts 26-3 willbe retightened. This adjustability will be useful in connection with mounting the helical gears, on the ends of the upper and lower shafts, in aligned and properly meshed relation, as discussed above in connection with 7 FIGURE 2.

The left hand end of the shell 22h (not shown in FIG- URE 11') may be formed in a manner similar to the right hand end, with a shaft means similar to shaft 34h similarly drivingly connected thereto. The shaft means extending from either end of the shell 22h may be suitably mounted in the machine of FIGURE 1 and be drivingly connected to the prime mover 44' on the one end and the gear 49 on the other end. The lower shell may be similarlyconnected to separate shaft meansextending from opposite ends thereof and also suitably arranged in the bearings 39. Slots Silk, 5211 are shown as being provided on the upper shell 22h, and corresponding slots manner shown in FIGURE 2, to facilitate alignment of the patterns on the upper and lower shells in precise FIGURE 13 illustrates still another embodiment of structure according to the invention for mounting hollow embossed shells in mating relation and in operative position, for example, in the machine 2% shown in FIGURE 1. In this embodiment, the shells 22i, 24: are formed with a tapered internal bores 234, 236, respectively, extending throughout their entire lengths, and the helical gears fi-tli, 42i, are fixedly secured in predetermined orientation to their respective shells, .as by bolts 238 extending through the gears and screwed into threaded holes 249 in the shells, and also by tapered pins 242 mounted in aligned holes 246, 248 in the gears 4th, 42i and shells 2211.241, respectively. a

The shafts 250, 252 for the shells are formed with tapered sections 254, 255 complementary to the tapered V bores 234, 236 of the shells whereby the shells may be engaged thereover, as shown. The gears etli, 421', carried by the shells, will be fitted over shaft portions 258, 2613 of uniform diameter, and drivingly connected thereto in any appropriate manner. For example, the shaft portions 258, 260 may be provided with keyways 262, 264, respectively, adapted to receive keys (not shown) extending in complementarily-shaped keyways in the gears 49L 42i, as will be understood.

The gears 40i, 42i'will be providedwith means thereon, such as the marks 68, 7 0 shown in the gears in FIGURE 2, so that when these'marks are in perfect radial alignment, as shown in FIGURE 2, the patterns on the shells V 22i, 24i will be in precise registration, and the gears will be in precise meshing relation.

may be formed on the lower shell (not shown) as in the Nuts 266, 268 are'secured to threaded portions 270,

' 272 on the shafts 250, 252, respectively, and are adapted to be tightened thereon against the gears 40L 4-2i in order to hold the shells 221', 24i in proper position on'their respective shafts. Standard lock washers 274 may be arranged between these nuts and the gears, as shown.

Bearings 128i and 30f are engaged to the upper shaft 25!? and lower shaft 252, respectively. The two right hand bearings 28i and 3th andthe right hand ends of the shafts 213i), 252. are shown'as being of identical construction.

engagement with the shafts 250, 252 at one end of these boxes, and a closure plate 292 is detachably'secured to the other end of the bearing box, as shown.

'An axial passageway 294 is provided in each of the shafts 25%, 252 extending from the right handend thereof to the tapered sections 254, 256 where they communicate by means of a radial bore296 with 'a circumferential groove 29% on the external surface ofthe tapered sections.

Thus, oil may be delivered through passageways 294 to the circumferential grooves 228 toassist in stripping the shells 221', 241' from their respective shafts.

The bearings forthe left hand ends of the shafts 250, 252 are fixed bearings. Asshown, the upper bearing 23i is arranged within a bearing box 3% open at both ends. This bearing 28i engages against a shoulder 392 on the shaft 250, and the shaftextends through this bearing and the bearing box, providing a portion 304 adapted to be drivingly connected to the prime mover i i-through the coupling 48. For this purpose, the portion 394 is shown as including akeyway 3%. I

A sleeve 398 is-arranged around. the shaft 250 in engagement with the left hand bearing 28i and a lock nut 31% is screwed onto a threaded portion of the shaft and tightened against this sleeve3i3$ in order to hold the bearing 23: inthe position shown. Sealing rings 312 of suitable material are carried by the bearing box 30% encircling the shaftZStl and sleeve 308' and in fluid sealing engagement therewith.

The lower left hand bearing 350i is also a fixed bearing, and is arranged in a bearing box 314 and in engagement with the end portion 316 of shaft 252. A lock nut 318 is screwed onto the threaded left hand end'of the shaft 252 and cooperates with a shoulder 32% on the shaft for retaining the bearing 30% in the position shown relative to the shaft. The right hand end of bearing box 314 is open to receive the shaft 252, and a sealing ring 322 is mounted in this end of the box in encircling fluid sealing engagement with the shaft 252, as shown. A closure plate 324- is detachably connected to the left hand end of the box.

Adjusting screws 326 are shown canied by the closure plate 324 and the right hand side of the bearing box 314,

extending through threaded holes into engagement with 1 the sides of bearing 30L and permitting adjustment of the position thereof, as will be apparent. Lock nuts 328 are provided for retaining these screws in proper position, once they are adjusted,

The bearing boxes 288-, 282, 3% and 314 may be arranged in the stanchions or uprights 26015 the machine 2%, shown in FIGURE 1, in anylsuitable manner, as should be evident, to mount the shells 22:, 24i in operative embossing position. As previously stated, the gears 401', 42L when engaged to their respective shells 221', 241' will be so oriented that when these geafs are brought into meshing relation with the 'marks 68, 7t thereon (see FIGURE 2)' in proper alignment, the patterns on the shells 222', 242' will be in precise registration with each other.

It will be appreciated that the structures shown in the various embodiments of the invention described above not only will enable the patterns on the embossing shells to be arranged in precise'registration with each other when the shells are mounted in operative, embossing position, but they will also greatly facilitate changeover from one set of embossing shells having a certain pattern thereon to another set of embossing shells having a different pattern thereon, inasmuch as the shells may be conveniently detached from their respective shaft means, and the desired set of shells attached thereto, as will be understood from the foregoing description. Furthermore, the hollow embossing shells of the present invention conta n considerably less material than conventional solid embossing shells, and hence, will be less expensive to make, thereby enabling manufacturers of embossed sheet materials to offer a plurality of different designs in their embossed sheet material products without requiring the large capital investment that would be involved if sets of solid embossing rolls having the desired patterns thereon had to be purchased.

The present invention will thus be seen to completely I and effectively accomplish the objects enumerated hereinabove. it will be realized, however, that various changes and substitutions may be made to the specific embodiments disclosed herein for the purpose of illustrating the principles of this invention, without departing from these principles. Therefore, this invention includes all modifications encompassed within the spirit and scope of the following claims.

What is claimed is:

l. A method of preparing and assembling in an operative position a pair of matched and hollow embossing shells having mating patterns thereon, said method comprising: forming mating patterns on the external cylindrical surface of each of two hollow metallic shells of substantially the same size; providing substantially similar slots in predetermined locations in corresponding radial end faces of said shells so that when said slots are brought into precise radial alignment the patterns on said shells will be precisely mated; mounting said shells in rotatable positions in coextensive and substantially close relation with their axes parallelgrotating one of said shells relative to the other shell While maintaining said shells in bodily stationary position and until said slots are brought into precise radial alignment; and securing said shells in this position and in driving connection with each other.

2. A method of preparing and assembling in an operative position a pair of matched and hollow embossing shells having mating patterns thereon, said method comprising: drivingly attaching a first gear to a first hollow embossing shell in a predetermined orientation relative to the pattern on said first shell; drivingly attaching a second gear to a second hollow embossing shell in a predetermined orientation relative to the pattern on said second shell; said first and second shells having mating patterns thereon; providing visually alignable meanson said gears and bringing the shells into relative radial positions wherein the mating patterns are precisely aligned with each other; and mounting said shells and gears for rotation in coextensive and contiguous, parallel relation, with said gears being meshed together and then bringing the shells into relative radial positions so that the mating patterns are precisely matched by aligning the aligning means.

3. Structure of the character described comprising a pair of matched cylindrical embossing shells having uninterrupted interior surfaces and having mating patterns thereon, shaft means drivingly and coaxially connected to each of said shells and extending axially outwardly therefrom at opposite ends thereof, means engaging said shaft means for rotatably mounting said shells coextensively and in substantially close relation with their axes in parallel, and alignable means operatively 7 id associated with said shells and constructed'and arranged to be brought into radial alignment by relative rotation between said shells whereby to assure precise alignment of the patterns on said shells.

4. The structure defined in claim 3 wherein said alignable means comprises a radial slot formed in a radial end surface of each of'said shells.

5. The structure defined in claim 3 wherein said slots are exposed.

6. The structure defined in claim 3 wherein a gear is fixedly coaxially attached to each of said shells in a predetermined orientation relative to the pattern on the shell, said alignable means being arranged on exposed faces of said gears.

7. Structure of the character described comprising a pair of matched cylindrical embossing shells having mating patterns thereon and having tube-like interior surfaces, shaft means drivingly and coaxially connected to each of said shells and extending axially outwardly therefrom at opposite ends thereof, means for indicating precision alignment of said mating patterns with respect to one another, means engaging said shaft means for rotatably mounting said shells coextensively with their axes in parallelism, a source of power drivingly connected to one of said shaft means externally of one end of one of said shells, meshing gears on said shaft means at the other end of said shells and drivingly connected to said shells for transmitting rotation between said shells, means providing for lost motion in the driving connection between one of said shells and one of said gears, and alignable means on said gears adapted to be brought into alignment by relative rotation between said one gear and said one shell as permitted by said lost motion.

8. Structure of the character described comprising: a pair of shafts; means rotatably arranging said shafts in parallel relation; each of said shafts including a tapered section, said sections being substantially co-extensive and of the same taper; a pair of hollow embossing shells provided with mating patterns thereon and each of said shells having a bore tapered throughout and complementary to said tapered section; said shells being arranged coaxially over said tapered sections in engagenient with each other; means drivingly connecting said shafts together; and means drivingly connecting each of said shells to its respective shaft.

9. The structure defined in claim 8 and further including means operatively associated with said shells and capable of indicating whether or not the patterns on said shells are in precise registration with each other.

10. Structure of the character described comprising: a pair of shafts; means rotatably arranging said shafts in parallel relation; each of said shafts including a tapered section, said sections being coextensive and of the same taper; a pair of hollow embossing shells provided with mating patterns thereon and each of said shells having a bore of a taper complementary to said tapered sections; said shells being arranged coaxially over said tapered sections and in engagement with each other; a gear drivingly mounted on each of said shafts in engagement with an end face of the shell on said shaft adjacent the narrow portion of said tapered section, said gears being meshed together; and means drivingly connecting said gears to said shells.

11. The structure defined in claim 10 wherein radially alignable marks are provided on the exposed faces of said gears and constructed and arranged so that when radially aligned, the patterns on said shells are in precise registration.

12. A method of detachably assembling in an operative position a pair of matched, cylindrical embossing shells having mating patterns thereon comprising: mounting said shells in rotatable positions with their patterns in closely adjacent relationship, the axis being parallel, said shells having cooperating radially aligned members; and rotating one of said shells relative to the other shell r 11 while maintaining said shells at a stationary distance from one another and bringing the aligned members in precise alignment so that the patterns of saidshells are in precise relation each to the other. 1 i 13. Method of forming embossing rolls comprising the stepsof: forming an embossing pattern on the outer surface of a cylindrical til-behaving tube-like inner and outer surfaces; forming a mating embossing patternon the outer surface on a second cylindrical tube having tube-like inner and outer surfaces; mounting said tubes to drive shafts and supporting said tubes in concentric relationship thereto; positioning said drive shafts in parallel relationship With said embossing patterns adjacent; and rotatably adjusting one of said tubes Wth respect to the other to bring the patterns into precise alignment.

I 14. Method of forming an embossing roll comprising: forming an embossing pattern'about the exterior surface of a cylindrical shell having a tube-like interior surface; positioning a drive shaft concentrically within said tube;

positioning tube supporting members on said shaft to concentrically support said tube with respect to said drive shaft.

15. Structure of the character described comprising a pair of tubular cylindrical embossing shells having mating patterns thereon, said shells having tubelike interior surfaces, drive shaft means positioned concentrically within said shells in axial alignment relative toone another;

tube supporting means carried by said shafts for engaging the inner surface of the respective shells to position the same in concentric relationship; and means cooperaing with said shell and shell supporting means for rotatably adjusting the position of Said tube with respect to said shaft; and means for indicating alignment of said patterns in precision relationship with one another.

16. Structure defined in claim 15 wherein said tubes are outwardly tapered at the opposed ends thereof, said 1 supporting mean including opposed frusto-conical flanges engaging said tapered surface at the outer ends thereof, said. adjusting means including adjustable pin means.

References Cited in the file of this patent UNITED STATES PATENTS 

